This invention is concerned with absorbent articles such as sanitary napkins, pantiliners, and incontinent pads that are designed to absorb and retain liquid and other discharges from the human body and to prevent body and clothing soiling. The present invention is particularly concerned with sanitary napkins that are generally relatively thin and flexible.
Sanitary napkins of a wide variety of shapes and dimensions are currently used by women for the collection of menses and other bodily discharges.
With respect to sanitary napkins, at least two general classes pertinent to the present invention exist. One such class is for the absorption of medium to high menstrual flows. These sanitary napkins offer a fairly high absorptive capacity. Absorptive capacity is commonly achieved by providing the napkin with a fairly thick and bulky absorbent member, commonly fluff pulp. Sanitary napkins of this class are disclosed in U.S. Pat. No. 3,294,091 which issued to Morse on Dec. 27, 1966 and U.S. Pat. No. 4,654,040 which patent issued to Luceri on Mar. 31, 1987.
Such sanitary napkins theoretically have a high absorptive capacity, however, when the sanitary napkin is worn and subjected to the compressive forces of the wearer's thighs and pudendal region, the fluff pulp core simply compacts or bunches into an arbitrary, but generally rope-like shape. Such napkins commonly shift from their original placement so that after only a short wearing time, the napkin might only partially, if at all, be beneath the wearer's vaginal orifice or vestibule. Thus, in use, these sanitary napkins sometimes offer very little absorption. Further, the rolling and twisting of these napkins may create soiling on the wearer's panties and skin surfaces. In addition, the bulkiness of these napkins causes a high degree of wearing awareness and may make them quite obtrusive when worn with tight fitting slacks, body suits or bathing suits.
A second class of sanitary napkins are intended for light or low menstrual flows and are commonly referred to as panty liners or panty shields. Sanitary napkins of this type are disclosed in U.S. Pat. No. 4,681,578, entitled "Pantiliner With Ventilation Areas", which patent issued to Anderson and Brandt on Jul. 21, 1987. Sanitary napkins of this class, as a group, are thinner, somewhat more flexible and generally more comfortable than those of the first class, however, they lack the absorptive capacity of the napkins of the first class.
Recently, efforts have also been directed at developing thin sanitary napkins which have the capacity to absorb and contain medium to high menstrual discharges. Previously, such discharges could only be handled by relatively thick sanitary napkins. Examples of thin sanitary napkins having capacities great enough to handle medium to high menstrual flows are disclosed in U.S. Pat. Nos. 4,950,264 and 5,009,653, issued to Osborn, III, on Aug. 21, 1990 and Apr. 23, 1991, respectively. The disclosures of both of these patents are incorporated by reference herein.
It is also desirable that sanitary napkins conform as closely as possible to the body of the wearer. Such a body-conforming capability is believed to increase the effectiveness of the sanitary napkin by reducing the possibility that menses will travel around the perimeter of the sanitary napkin and leak. There have been a number of recent efforts to provide sanitary napkins and other absorbent articles with improved body-conforming characteristics. In addition to serving as examples of thin sanitary napkins, the sanitary napkins disclosed in the above-mentioned Osborn patents also serve as examples of anatomically-conforming sanitary napkins. Other examples of anatomically-conforming sanitary napkins are disclosed in European Patent Application publication numbers 0 335 252 and 0 335 253 published Oct. 4, 1989 in the name of Kenneth Barclay Buell, which are also incorporated by reference herein.
One attempt to reduce the tendency of a thin sanitary napkin to twist and bunch during use is described in Kimberly-Clark European Patent Application Publication Number 0 471 114 A2 published Feb. 19, 1992. This publication is also incorporated by reference herein. The Kimberly-Clark European Patent Application discloses providing a thin sanitary napkin with a thin "central zone" that has greater stiffness than adjacent portions of the napkin.
While the sanitary napkins disclosed in the Osborn patents and the Buell patent applications work quite well, the search for improved sanitary napkins has continued.
Therefore, there exists a real consumer need for a sanitary napkin which is generally thin and flexible, thereby offering enhanced fit and comfort, yet having a fluid capacity great enough for use with medium to high menstrual flows. The present application is directed to a number of such sanitary napkin embodiments.
It is an object of the present invention to provide a sanitary napkin which is generally thin and flexible and which is absorbent enough to absorb and contain medium to high menstrual flows.
It is an additional object of the present invention to provide a sanitary napkin which will closely conform to the various anatomical shapes of the female urogenital region, and, in particular, will easily form around the curvature of the wearer's labia majora by cupping and surrounding the exterior of the labia majora.
It is an additional object of the present invention to provide a sanitary napkin which offers enhanced fit and comfort and a low degree of wearing awareness.
These and other objects of the present invention will be more readily apparent when considered in reference to the following description and when taken in conjunction with the accompanying drawings.